In particular, motor vehicles that possess an electric motor that is energized by way of a rechargeable battery also comprise a charging device in order to recharge the battery from an external electrical energy source. In this case, it has been proposed to design such charging devices as inductive devices, wherein an induction device on the side of the motor vehicle, this device being usually designed as a charging coil, is positioned overlapping as accurately as possible an induction unit underneath it, in order to make possible an optimal inductive energy transmission. In other words, there exists a target position in which the charging coil and the induction unit underneath it are positioned optimally to each other, and which is accordingly to be adopted preferably by the motor vehicle.
Since the motor vehicle-side induction device with the charging coil is situated at the bottom of the motor vehicle, usually either in the front or the rear region of the motor vehicle, and moreover, the induction unit underneath it is covered over during the maneuvering of the motor vehicle for the best possible overlapping of the induction unit, it is extremely difficult for a driver to achieve an occupying of the optimal target position that is the most accurate as possible, so that various assistance methods have been proposed to assist the driver in the most optimal positioning of the motor vehicle relative to the induction unit underneath it. For example, it has been proposed to use front and rear cameras, whose images are indicated on a display as an optical indication means in the motor vehicle in order to assist the proper positioning of the motor vehicle on top of the induction unit underneath.
DE 20 2017 101 526 U1 relates to inductive charging equipment orienting systems for motor vehicles. It is proposed here to actuate a headlamp, which is coupled to a corresponding control device, in such a way that an alignment between a receiving winding and an offboard inductive transmitting winding is reported to the driver of the motor vehicle. In particular, a light pattern can be projected onto a wall. However, in the absence of a wall, the information output in this way can hardly be used by a driver.
DE 10 2014 222 000 A1 relates to a method and a floor unit for inductive charging of electric and hybrid motor vehicles. The floor unit here comprises an image sensor, which is designed to detect image data from at least a portion of the motor vehicle. A control unit is designed to provide or to use the image data for a positioning of the secondary coil relative to the primary coil. Therefore, in this case also, image data is provided to the driver, especially on a display, but he can only evaluate and interpret it poorly and by looking away from the actual maneuvering environment.
DE 10 2015 215 127 A1 relates to the automatic positioning of a motor vehicle, wherein a light signal is transmitted between a first light source and a photodetector, and a second light signal is transmitted between a second light source and the photodetector. Position data is determined, which is instructive for positioning a motor vehicle in relation to a target, whereby the motor vehicle is steered to approach the target.